Demon masters are demons who possess greater power than typical demons. Demon masters have been described as powerful and commanding. They are often served by lesser demons who seek refuge and protection in return. The most notable example of a demon master in the Demonata series is Lord Loss who makes an appearance in every book.
Demon masters are known to be able to manipulate magic better than lesser demons. They possess a far stronger flow of magical energy; their presence is often felt before they are seen. Some demon masters can create their worlds with rules that are ideal to the master. This makes it virtually impossible to beat a demon master in their own world.
Demon masters are so powerful infact that regular windows wont allow them to cross between worlds. They need a tunnel wide enough to capacitate their magical power and sometimes physical size. Their is only one demon master known in the series that can cross worlds as freely as lesser demons because he was once host to a piece of the Kah-Gash.